1. Field of the Invention
The present invention relates to a capacitor device and a method of manufacturing the same and, more particularly, a capacitor device that is arranged on a circuit substrate and applicable to a decoupling capacitor, a high-frequency filter, and the like and a method of manufacturing the same.
2. Description of the Related Art
In the prior art, there is the capacitor device that is arranged on the circuit substrate and functions as a decoupling capacitor, a high-frequency filter, or the like. In the method of manufacturing the capacitor device in the prior art, as shown in FIG. 1A, a first copper layer 102a is formed on a substrate 100, then a photosensitive dielectric layer 104a is formed thereon by a roller coater, or the like, and then a second copper layer 106a is formed on the dielectric layer 104a. In case the dielectric layer is formed by the roller coater, or the like, it become difficult to get the dielectric layer having a uniform film thickness when a surface of the underlying layer is uneven. Therefore, the dielectric layer 104a is formed on the flat first copper layer 102a. 
Then, as shown in FIG. 1B, upper electrodes 106 for a capacitor are formed by patterning the second copper layer 106a. Then, the photosensitive dielectric layer 104a is exposed/developed while using the upper electrodes 106 as a mask. Thus, dielectric layer patterns 104 are formed under the upper electrodes 106 respectively.
Then, as shown in FIG. 1C, dry film resists 110 used to form a lower electrode are patterned on the upper electrodes 106 and the first copper layer 102a, and then the first copper layer 102a is etched by using the dry film resists 110 as a mask. Then, the dry film resists 110 are removed.
Thus, as shown in FIG. 1D, lower electrodes 102 are formed under the dielectric layer patterns 104 respectively. As a result, capacitors C each consisting of the lower electrode 102, the dielectric layer pattern 104, and the upper electrode 106 are obtained.
As described above, in order to ensure uniformity in the film thickness of the dielectric layer formed by the roller coater, such an approach was employed in the prior art that the dielectric layer 104a and the second copper layer 106a are formed on the flat first copper layer 102a, then the upper electrodes 106 and the dielectric layer patterns 104 are formed on the first copper layer 102a, and then the lower electrodes 102 are formed by patterning the first copper layer 102a. 
As described above, in the method of manufacturing the capacitor device in the prior art, the dry film resist 110 must be patterned on a level difference caused by the dielectric layer pattern 104 and the upper electrode 106. For this reason, the dry film resist 110 cannot follow up such level difference, and thus a clearance A (FIG. 1C) is formed on the peripheral portion of the level difference.
Therefore, when an interval between a plurality of capacitors is narrowed (almost 200 μm or less), a defect such as a pattern separation of the dry film resist 110, or the like is caused, and thus it becomes difficult to form the lower electrodes 102 with good precision. As a consequence, in the prior art, an unnecessary wide interval must be provided between a plurality of capacitors, which prevents a miniaturization of the capacitor device.